共查询到19条相似文献,搜索用时 171 毫秒
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多输入多输出(Multiple Input and Multiple Output,MIMO)信道的空间相关性极大程度上影响着MIMO系统的性能.基于相关统计建模的空间相关性MIMO信道模型,通过合理的软硬件划分,设计了一种高资源利用率的MIMO信道实时模拟方案,实现了实时MIMO信道模拟器.针对3GPP标准MIMO信道模型进行模拟,硬件模拟结果统计分析表明本方案模拟的MIMO信道特征能够与理论特征很好地吻合,具有良好的模拟精度.可扩展的信道模拟方案能够直接扩展到支持更多天线数目的MIMO信道的实时模拟. 相似文献
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研究了基于空间信道模型(SCM)的空域相关矩阵,搭建了MIMO通信信道仿真平台,同时考虑时延扩散、多普勒效应、波达方向及角度扩散等多种信道参数,通过蒙特卡罗方法计算了MIMO系统的信道容量、空时相关性、衰落特性及功率延迟分布特性.指出了在信道的去极化作用下,无线通信系统的多径衰落可以采用极化分集和天线分集等技术进行克服,平均入射角对系统性能起着关键的作用. 相似文献
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针对多输入多输出(Multiple-Input Multiple-Output,MIMO)无线传播环境,综合考虑路径损耗、阴影衰落和多径衰落影响,提出一种基于Nakagami-Lognormal分布的相关复合衰落MIMO信道模型,推导并获得各信道自相关和互相关系数的理论表达式;提出一种基于谐波叠加思想的复合衰落MIMO信道仿真方法,并分析了该方法输出信道衰落的空时相关特性.数值仿真结果表明:仿真模型输出统计特性均与理论模型吻合;各子信道之间存在互相关性且随阴影衰落方差减小而下降,而自相关性则呈现快速起伏并缓慢下降的特性. 相似文献
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数据的高速率传输以及终端的高速移动,导致无线通信信道具有时间选择性与频率选择性两个特征。该文主要研究了数据分组传输方式下,基于导频符号辅助调制(PSAM)的多输入多输出(MIMO)时间-频率双选择性信道的信道估计问题。首先,将时间-频率双选择性MIMO信道,建模为一个随时间变化的多项式内插信道模型;然后,根据信道Doppler衰落速率、多项式模型中的误差项,确定出模型的阶数以及整个数据块的长度;最后,基于该多项式内插信道模型,提出了采用PSAM的MIMO双选择性信道估计方法。实验结果表明该算法在时间-频率双选择性衰落信道下具有较好的性能。 相似文献
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数据的高速率传输以及终端的高速移动,导致无线通信信道具有时间选择性与频率选择性两个特征.本文主要研究了数据分组传输方式下,基于导频符号辅助调制(PSAM)的多输入多输出(MIMO)时间-频率双选择性信道的信道估计问题.首先,将时间-频率双选择性MIMO信道,建模为一个随时间变化的多项式内插信道模型;然后,根据信道Doppler衰落速率、多项式模型中的误差项,确定出模型的阶数以及整个数据块的长度;最后,基于该多项式内插信道模型,提出了采用PSAM的MIMO双选择性信道估计方法.实验结果表明本文的算法在时间-频率双选择性衰落信道下具有较好的性能. 相似文献
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针对TD-LTE射频一致性测试系统专项的需求及通用信道模拟器设计周期长、复杂度高的现状,研究了影响无线信道特性的路径损耗、阴影衰落、多径多普勒效应和高斯白噪声等因素,并相应提出了一种新的计算正余弦函数方法和高斯白噪声产生方法。通过信道理论建模、Matlab链路搭建进行模型优化分析以及基于Xilinx公司Virtex-6芯片的模型FPGA实现,得到了一种简单有效的信道模拟器。实验表明,用TD-LTE基带信号作为激励,该信道冲激响应与Matlab理论值误差在2‰之内,且模型不涉及SCM、WINNER等模型天线方向图、多链路等高复杂度模块,说明该信道模拟器具有简便性和可靠性。 相似文献
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Multiuser MIMO OFDM Based TDD/TDMA for Next Generation Wireless Communication Systems 总被引:1,自引:1,他引:0
Multiple-input multiple-output (MIMO) wireless technology in combination with orthogonal frequency division multiplexing (MIMO
OFDM) is an attractive air-interface solution for next-generation wireless local area networks (WLANs), wireless metropolitan
area networks (WMANs), and fourth-generation mobile cellular wireless systems. In this paper, one multiuser MIMO OFDM systems
with TDD/TDMA was proposed for next-generation wireless mobile communications, i.e., TDD/TDMA 4G, which can avoid or alleviate
the specific limitations of existing techniques designed for multiuser MIMO OFDM systems in broadband wireless mobile channel
scenarios, i.e., bad performance and extreme complexity of multiuser detectors for rank-deficient multiuser MIMO OFDM systems
with CDMA as access modes, extreme challenges of spatial MIMO channel estimators in rank-deficient MIMO OFDM systems, and
exponential growth complexity of optimal sub-carrier allocations for OFDMA-based MIMO OFDM systems. Furthermore, inspired
from the Steiner channel estimation method in multi-user CDMA uplink wireless channels, we proposed a new design scheme of
training sequence in time domain to conduct channel estimation. Training sequences of different transmit antennas can be simply
obtained by truncating the circular extension of one basic training sequence, and the pilot matrix assembled by these training
sequences is one circular matrix with good reversibility. A novel eigenmode transmission was also given in this paper, and
data symbols encoded by space–time codes can be steered to these eigenmodes similar to MIMO wireless communication systems
with single-carrier transmission. At the same time,, an improved water-filling scheme was also described for determining the
optimal transmit powers for orthogonal eigenmodes. The classical water-filling strategy is firstly adopted to determine the
optimal power allocation and correspondent bit numbers for every eigenmode, followed by a residual power reallocation to further
determine the additional bit numbers carried by every eigenmode. Compared with classical water-filling schemes, it can also
obtain larger throughputs via residual power allocation. At last, three typical implementation schemes of multiuser MIMO OFDM
with TDMA, CDMA and OFDMA, i.e., TDD/TDMA 4G, VSF-OFCDM and FuTURE B3G TDD, were tested by numerical simulations. Results
indicated that the proposed multiuser MIMO OFDM system schemes with TDD/TDMA, i.e., TDD/TDMA 4G, can achieve comparable system
performance and throughputs with low complexity and radio resource overhead to that of DoCoMo MIMO VSF-OFCDM and FuTURE B3G
TDD. 相似文献
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In this paper, we have analyzed the performance of maximal ratio combing (MRC) diversity receiver of the wireless communication systems over the composite fading environment, which is modelled by using the generalized-K distribution. However, this distribution has been considered as a versatile distribution for the precise modelling of a great variety of the short-term fading in conjunction with the long-term fading (shadow fading) channel conditions. In this proposed analysis, we have derived the mathematical expression for the moment generating function (MGF) of the generalized-K fading channel model that is used to evaluate a novel closed-form expression of the average bit error rate for (BER) the binary phase-shift keying /binary frequency-shift keying and average symbol error rate (SER) for the rectangular quadrature amplitude modulation scheme. We have also derived the mathematical expressions for the outage probability as well as the channel capacity for the generalized-K fading channel model. 相似文献
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A low-complexity hardware emulator is proposed for wideband, correlated, multiple-input multiple-output (MIMO) fading channels.
The proposed emulator generates multiple discrete-time channel impulse responses (CIR) at the symbol rate and incorporates
three types of correlation functions of the subchannels via Kronecker product: the spatial correlation between transmit or
receive elements, temporal correlation due to Doppler shifts, and inter-tap correlation due to multipaths. The Kronecker product
is implemented by a novel mixed parallel-serial (mixed P-S) matrix multiplication method to reduce memory storage and to meet
the real-time requirement in high data-rate, large MIMO size, or long CIR systems. We present two practical MIMO channel examples
implemented on an Altera Stratix III EP3SL150F FPGA DSP development kit: a 2-by-2 MIMO WiMAX channel with a symbol rate of
1.25 million symbols/second and a 2-by-6 MIMO underwater acoustic channel with 100-tap CIR. Both examples meet real-time requirement
using only 12–14% of hardware resources of the FPGA. 相似文献
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一种分布式多入多出(MIMO)信道的容量研究 总被引:11,自引:1,他引:10
分布式MIMO系统结合了点对点MIMO信道与分布式天线系统两者的特点,能改善链路的质量,提高覆盖面积。本文提出了一种包含路径损耗、阴影衰落与小尺度衰落的分布式MIMO信道模型,分析推导了采用该模型时的分布式MIMO信道容量。通过计算机仿真,研究分析了阴影衰落、Rice信道因子K等因素对分布式MIMO上行信道容量的影响,得出了分布式MIMO信道容量空间分布的特点。 相似文献
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几种接收机在MIMO信道下的性能比较 总被引:1,自引:0,他引:1
多入多出(MIMO)无线信道具有空间复用增益和分集增益特性,因此MIMO系统和单入单出(SISO)无线系统相比能够获得更高的频谱效率。本文在不同天线组合下分析了几种MIMO空时信号处理算法的性能,仿真结果和理论分析表明:空间复用增益和分集增益不能同时获得最大,因此在设计MIMO通信系统时可根据实际情况选择天线数,即不仅考虑系统抵抗信道衰落的分集增益,还要考虑能够提供更高的数据传输速率,通过折衷考虑空间复杂增益和分集增益,从更全面的观点评估系统的性能。 相似文献
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To solve the problems of pulse broadening and channel fading caused by atmospheric scattering and turbulence, multiple-input multiple-output(MIMO) technology is a valid way. A wireless ultraviolet(UV) MIMO channel estimation approach based on deep learning is provided in this paper. The deep learning is used to convert the channel estimation into the image processing. By combining convolutional neural network(CNN) and attention mechanism(AM), the learning model is designed to extract the depth f... 相似文献